1. Field of the Invention
The present invention relates to a method and device which easily measure ultraviolet rays existing in a living environment. In further detail, the present invention relates to an ultraviolet ray measuring method and an ultraviolet ray measuring device which can acquire specific ultraviolet ray information such as, for example, the ultraviolet ray amount directly acting on a human body.
2. Description of the Related Art
One of the greatest global environmental problems in recent years is that the ultraviolet ray amount on the earth is increasing due to the destruction of the ozone layer. Ultraviolet rays have serious effects on health, such as the occurrence of skin cancer, an increase in photosensitivity due to damage to DNA, photoaging, and the like. The effects on skin which are problematic from a cosmetic standpoint, such as liver-spots, freckles, and the like, are also great.
The necessity to measure ultraviolet rays in the living environment is increasing from the standpoints of cosmetics, medicine, and the like.
In order to measure the ultraviolet ray amount, an ultraviolet ray gauging device used exclusively for such a purpose is needed. However, it is bothersome to carry such an exclusive-use UV gauging device around, and from this standpoint as well, it has conventionally not been possible to easily measure ultraviolet rays.
The effects of ultraviolet rays on organisms are varied. Therefore, there are various ways of expressing the ultraviolet ray amount, depending on what the measured ultraviolet rays mean. For example, there is a method of expressing the total ultraviolet ray amount (wavelength: about 290 to 400 nm), a method of measuring by using an ultraviolet ray sensor having sensitivity in only the UVA region (wavelength: about 320 to 400 nm), a method using an ultraviolet ray sensor having sensitivity in only the UVB region (wavelength: about 290 to 320 nm), and the like.
However, these ultraviolet ray sensors which measure ultraviolet rays do not have a characteristic matching the erythema curve which causes symptoms of sunburn of the skin, and do not have measured values which are delta-functionally obtained in the defined wavelength region, and are calibrated at a sensitivity to a representative wavelength within a specific spectral sensitivity curve. The index determined from the erythema curve is called the UV index.
The UV index is an amount of energy in which the weight of the erythema curve is applied to ultraviolet rays of one hour around noon. Generally, the UV index is quantitatively divided into ten numerical levels from solar ultraviolet rays, but is divided into 5 levels in common parlance suited to the senses of people.
The UV index is determined by applying a weight for each wavelength in the UVB region. Accordingly, no accurate value can be obtained other than by determining the UV index from the spectral illuminance. Measurement can only be carried out by using a large measuring device, and cannot be carried out easily. Further, with a measuring device having a spectral sensitivity matching the erythema ultraviolet rays, conversely, ultraviolet rays such as UVA and the like cannot be measured, and there is the problem that attention cannot be paid to ultraviolet rays which pass through windows and which have great cosmetic effects such as liver-spots, freckles, and the like.
Therefore, the current situation is that there is no method by which specific ultraviolet ray information can be easily measured, and improvements are desired.